Multiple frame grabber

ABSTRACT

A system is presented that applies M×N×K computational units to calculating image parameters on N picture images captured simultaneously by N digital camera devices, where there are N groups of frame grabber units, each containing M frame grabbers in which there are K computational units. The data operated on by a computational unit is separate and independent from the image data operated on by the other computational units. This results in a performance speedup of M×N×K compared to one computational unit making the same computations. A master frame grabber unit controls the illumination of the N digital camera devices, and synchronizes the illumination with the clocks of the N digital camera devices.

This is a divisional application of U.S. patent application Ser. No.10/980,481, filed on Nov. 3, 2004now U.S. Pat. No. 7,567,273, which isherein incorporated by reference in its entirety and assigned to thesame assignee.

RELATED PATENT APPLICATION

This application is related to U.S. patent application Ser. No.10/930,351, filed on Aug. 31, 2004, now issued as U.S. Pat. No.7,486,309 and assigned to the same assignee as the present invention.

This application is related to U.S. patent application Ser. No.10/929,651, filed on Aug. 30, 2004, now issued as U.S. Pat. No.7,505,064 and assigned to the same assignee as the present invention.

This application is related to U.S. patent application Ser. No.10/930,353, filed on Aug. 31, 2004, now issued as US Patent PublicationNo. 2006/0038916, and assigned to the same assignee as the presentinvention.

This application is related to U.S. patent application Ser. No.10/929,652, filed on Aug. 30, 2004, now issued as U.S. Pat. No.7,155,119 and assigned to the same assignee as the present invention.

This application is related to U.S. patent application Ser. No.10/929,300, filed on Aug. 30, 2004, now issued as U.S. Pat. No.7,248,347 and assigned to the same assignee as the present invention.

This application is related to U.S. patent application Ser. No.10/929,653, filed on Aug. 30, 2004, now issued U.S. Pat. No. 7,403,229and assigned to the same assignee as the present invention.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention is related to the testing of light sensitivedevices and in particular to performing tests on digital camera andlight sensor devices at a wafer level or a packaged module level.

2. Description of Related Art

The digital camera is becoming a ubiquitous device. Not only are digitalcameras replacing the traditional film camera, digital camera devicesare being used in many other applications, such as small electronicdevices, such as PDA (personal data assistant) and cellular phones. Withthe explosion of cellular phones, the ability to take a picture and thensend that picture to another individual using a second cellular phonecomes the need to produce inexpensive digital camera modules andefficiently test these modules in large quantities. This is furthercomplicated by the many different module configurations that areemerging as a result of the many different application requirements,including fixed focus, manual focus and automatic focus as well asphysical size. The testing time for digital camera module, which canhave mega-pixel capability, has traditionally been a relatively longprocess (approximately sixty seconds for a module with 0.3 megapixels)to insure the integrity and picture quality of the camera. Thisnecessitates a testing capability, which insures the integrity andspecification of the digital camera module, and which is quick andhandles a large quantity of modules.

A patent application Ser. No. 10/417,317 dated Apr. 16, 2003, is relatedto miniature cameras and their manufacturing methods that are used asbuilt-in modules in hand held consumer electronics devices such asmobile phones and PDA's. In a second patent application Ser. No.10/434,743 dated May 8, 2003, a test system is described for digitalcamera modules used as built-in modules for consumer electronics, whichperforms electrical tests, adjustment of focus and sealing of the lensbarrel with glue.

In addition there are a number of other prior art patents that aredirected to testing of digital cameras: US 20040032496A1 (Eberstein etal.) is directed to a method of camera calibration and quality testing;EP 1389878A1 (Bednarz et al.) is directed to a method of cameracalibration and testing camera quality; US 20040027456A1 (Pierce)directed to the use of calibration targets; EP 1382194A1 (Baer) isdirected to dark current subtraction; JP 2003259126 (Keisuke) isdirected to remove noise of an image; US 20030146976A1 (Liu) directed toa digital camera system enabling remote monitoring; JP 2003219436(Fuminori) is directed to adjustment of a pixel shift camera; US2003142374 (Silverstein) is directed to calibrating output of an imageoutput device; JP 2003179949 (Hidetoshi) is directed to a luminancelevel inspection apparatus; JP 2003157425 (Vehvilainen) is directed toimproving image quality produced in a mobile imaging phone; JP2003101823 (Kenichi) is directed to specifying a picture data area; EP1286553 A2 (Baer) is directed to a method and apparatus for improvingimage quality; US 20030030648 (Baer) is directed to a method andapparatus for improving image quality in digital cameras; U.S. Pat. No.6,512,587 (Marcus et al.) is directed to measurement method andapparatus of an imager assembly; US 20030002749 (Vehvilainen) isdirected to a method and apparatus for improving image quality; US20020191973 A1 (Hofer et al.) is directed to a method and apparatus forfocus error reduction; WO 2002102060 A1 (Baer) is directed to a methodand apparatus for smear in digital images using a frame transfer sensor;JP 2002290994 (Hidetoshi) is directed to a method and apparatus todetect foreign matter on the surface of a lens; JP 200223918 (Yanshinao)is directed to an image inspection device and method, for a cameramodule; JP 2002077955 (Keisuke) is directed to a method and apparatusfor evaluating camera characteristics; JP 2001292461 (Keisuke) isdirected to a system and method for evaluating a camera; U.S. Pat. No.6,219,443 B1 (Lawrence) is directed to a method and apparatus forinspecting a display using a low resolution camera; U.S. Pat. No.6,201,600B1 (Sites et al.) is directed to a method and apparatus forinspection of optically transmissive objects having a lens; U.S. Pat.No. 5,649,258 (Bergstresser et al.) is directed to an apparatus andtesting of a camera; EP 0679932 B1 (Kobayashi et al.) is directed totesting an electronically controlled camera; U.S. Pat. No. 5,179,437(Kawada et al.) is directed to an apparatus for color correction ofimage signals of a color television camera; JP 03099376 (Hiroshi) isdirected to the quality of a display screen; U.S. Pat. No. 4,612,666(King) is directed to a pattern recognition apparatus; and U.S. Pat. No.4,298,944 Stoub et al.) is directed to a method and apparatus fordistortion correction for scintillation cameras.

SUMMARY OF THE INVENTION

It is an objective of the present invention to use parallel processingto compute image parameters on one or more digital camera devices undertest.

It is also an objective of the present invention to compute imageparameters of a plurality of digital camera devices simultaneously.

It is further an objective of the present invention to use a pluralityof groups of frame grabber units containing a plurality of computationalunits to capture images and calculate image parameters.

It is still further an objective of the present invention to distributean image to computational units within a frame grabber unit by pixel orgroup of pixels.

It is also further an objective of the present invention to control andilluminate a plurality of digital camera devices simultaneously toperform the same sequence of tests from which image data is created tobe analyzed by the plurality of computational units in the plurality offrame grabber units.

It is also still further an objective of the present invention toilluminate a plurality of digital camera devices with the same lightsource controlled by one frame grabber unit of the plurality of framegrabbers, whereby a first set of pictures are captured by the pluralityof digital camera devices and the light source is controlled to waituntil a second set of pictures are ready to be taken.

It is still further an objective of the present invention to illuminatea plurality of light sensors in chip form on a wafer, or in a packagedform, with a light system similar to that described herein, controlledby a frame grabber unit or a light control unit, and wherein the lightsource produces a light pulse having a defined color, shape, intensity,duration and repetition.

In the present invention a computational unit comprises a memorycontrolled by a field programmable gate array (FPGA), and a CPU thataccesses the memory to access image data from a digital camera deviceunder test (DUT) and returns calculated results to the memory. Thememory is coupled to a host computer to which the computed results arecoupled for combining into a final result and allow a decisionpertaining to the quality of the DUT that produced the image data.

The frame grabber controls the light source that is used to illuminatethe DUT, synchronizing the light source with the DUT and connectingresulting image data to a frame grabber unit. The frame grabber unitcomprises a plurality of computational units. Each computational unitoperates on data that is independent from other computational units andallowing parallel processing of the image data with no serial overheadother than the initial loading of each memory in each computationalunit. Computation can begin when the first pixel is loaded into amemory, allowing additional loading of the memory to be performed whilecomputation of a part of an image is being done.

A plurality of frame grabber units are coupled to a plurality of digitalcamera devices (N-DUT) with one frame grabber, considered a master,controlling the source of light that illuminates the plurality ofdigital camera devices. A plurality of images are captured by the N-DUTare coupled to the plurality of frame grabber units for computation. Aplurality of images are created by the N-DUT to be load the memories ofthe plurality of frame grabber units. So as not to impede the testprocess, the light source has a fast turn-on, turn-off and repetitionthroughout the change of colors and the shape of the light pulse. Theplurality of images captured by the N-DUT are distributed across theplurality of frame grabber units in such a way that all frame grabberunits are operating on pixels of the same image while additional imagesare created and delivered to the memories of the frame grabber units.

The DUT is a light sensitive semiconductor device located on asemiconductor wafer, or a carrier of unmounted devices, or the DUT canbe a module that has been assembled with a light sensitive device. Whena plurality of N-DUT is tested on a wafer or physically similar holdingdevice, a single light source can be used to illuminate all devices atthe same time. When a there is a plurality of part numbers located onseparate carrying devices, a separate light source may be required whereeach separate light source is controlled by a separate “master” framegrabber. In the case of modules the physical distance of the teststations may be far enough apart as to require separate light sources,even though the modules are of the same part number.

When distributing a picture image by individual pixel, the P pixels arecoupled to M frame grabber units, each of which contains K computationalunits. Computation on each pixel begins as soon as each pixel is loadedinto the memory of each computational unit. A first pixel P=1 is coupledto a first computational unit K=1 of a first frame grabber unit M=1, andcomputation is started. A P=2 pixel is coupled to a first computationalunit K=1 of second frame grabber unit M=2, and computation is started. AP=M pixel is then coupled to a first computational unit K=1 in an Mframe grabber unit, and computation is started. Then a P=M+1 pixel iscoupled to the K=2 computational unit of the M=1 frame grabber unit, andcomputation is started in the K=2 computational unit. The couplingprocess continues until M×K pixels have been coupled to all Kcomputation units in the M frame grabber units. Then the P=M×K+1 pixelis coupled to the memory of the K=1 computational unit of the M=1 framegrabber unit. The coupling of pixels continues until the last pixel of apicture has been coupled to one of the M×K computational units. When thecalculations on the P=1 pixel is completed the processor in the K=1computational unit commences calculations on P=M×K+1 pixel. The overlapof computation and the loading pixels into computational units allowsadditional time to make calculations. It should be noted that groups ofpixels forming a line, column or cluster can be coupled to the M framegrabber units in a fashion similar to that of coupling a pixel; howeverthe start of computation will not be fully overlapped with the couplingprocess until all the M frame grabber units have been loaded with aninitial group of pixels.

Alternatively, a P=1 pixel is coupled to a K=1 computational unit of theM=1 frame grabber unit, the P=2 pixel is coupled to a K=2 computationalunit of the M=1 frame grabber unit and continuing until a P=K pixel iscoupled to the K computational unit of the M=1 frame grabber unit. Eachtime a pixel is loaded into the memory of a computational unit,calculation of the parameters of the pixel is started. The P=K+1 pixelis coupled to the K=1 computational unit of the M=2 frame grabber unit.The P=2K pixel is coupled to the K computational unit of the M=2 framegrabber unit and the coupling of pixels to the frame grabber unitscontinues until the P=M×K pixel is coupled to the K computational unitof the M frame grabber unit. The P=M×K+1 pixel is then loaded into thememory of the K=1 computational unit of the M=1 frame grabber unit. Ifthe calculations being performed on the K=1 pixel are completed, theprocessor of the K=1 computational unit commences computation on theP=M×K+1 pixel. The process of coupling pixels to the computational unitscontinues until the last pixel of a picture image is coupled to acomputational unit of the M×K computational units. Calculations in eachM×K computational unit on the next pixel commences when the calculationson the pixel previously loaded in a computational unit are completed.

Additional frame grabber units and computational units can be addedalong with additional memory to allow for an increase in the number ofpixels, i.e. mega pixels and multiple mega pixels, in a picture image sothat calculation time for picture images of higher pixel count iscontrolled to be within an acceptable time. Also, a single lightcomprising of a set of mirrors can be used to provide illumination todevices that are remote from each other and would otherwise requireseparate light sources. This reduces the variability that can occurbetween a plurality light sources and the need to calibrate a pluralityof light sources to produce the same simultaneous.

Light sensors, which are not camera devices, in either wafer or packageform can be illuminated with a light source similar to the one describedherein. Where a frame grabber, or a similar control unit, controls alight source for intensity, color, shape, duration and repetition, withor without the use of mirrors to spread the light from a single lightsource over physical distances, to produce an illumination to enable thetesting of the light sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be described with reference to the accompanyingdrawings, wherein:

FIG. 1A is a block diagram of the present invention showing acomputational unit coupled to a device under test,

FIG. 1B is a block diagram of the present invention showing a pluralityof computational units within a frame grabber unit coupled to a deviceunder test,

FIG. 2 is a block diagram of the present invention of a plurality offrame grabber units coupled to a single device under test,

FIG. 3A is a block diagram of the present invention with two devicesunder test couple to separate light sources and frame grabber units,

FIG. 3B is a block diagram of the present invention with two devicesunder test couple to the same light source and separate frame grabberunits,

FIG. 4A is a block diagram of the present invention of two devices undertest, each coupled to a plurality of frame grabber units and separatelight sources,

FIG. 4B is a block diagram of the present invention of a plurality ofdevices under test, each coupled to a plurality of frame grabber unitsand one light source,

FIG. 5 is a flow diagram of a method of the present invention forcoupling a plurality of images to a plurality of computational units ina plurality of frame grabber units,

FIG. 6 is a flow diagram of a method of the present invention forcoupling for coupling pixels of an image to a plurality of frame grabberunits

FIG. 7 is a flow diagram of a method of the present invention forcoupling images from a plurality of devices under test to thecomputational units of a plurality of frame grabbers, and

FIG. 8 is a flow diagram of a method of the present invention forcoupling a plurality of digital camera devices to a same light sourceand a plurality of computational units to calculate image parameters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1A is shown a computational unit 10 of the present invention. Amemory 11 containing a field programmable gate array (FPGA) is used tostore image data 13 resulting from a light sensitive device such as adigital camera device under test (DUT) 14, where the FPGA controls theoperation of the memory. The DUT can be a light sensitive semiconductorchip or a module containing the chip. A pin electronics unit (PE) 16interfaces with the DUT 14 to provide signals and power to the DUT andreceives analog and digital signals back from the DUT. An analog todigital converter (ADC) forms part of the PE 16 to convert analog imagedata from the DUT into a digital format that is stored in the memory 11.The memory is coupled to a CPU 12 to perform calculations on the imagedata stored in memory 11 to determine the capability of the DUT to sensethe an image of light. Results from the calculations are stored backinto the memory 11 and the results are accessed from a host computer 15to determine a final composite test results. A select signal 17 is usedto select the memory and a “sync out” 18 is used to synchronize thememory with the incoming stream of image data.

In FIG. 1B is shown a frame grabber unit (FGU) 20 that contains aplurality of computational units 10 ranging from computational unit (1)to computational unit (K). A typical value for K is K=4, but K=8 or morecan be used depending upon the size of the computational task such asimages with megapixels. Each of the computational units 10 are coupledto the host computer 15, which gathers the results of the computationsfrom each memory 11 in the computational units 10 to form a compositeresult to determine the capability of the DUT to capture images of lightcoupled to the DUT.

Continuing to refer to FIG. 1B, image data is streamed into the framegrabber unit 20 and each FPGA contained within each computational unit(10) through computational unit (K) selects a portion of that data andstores it into memory 11 within the computational unit. The image dataselected can be by individual pixel or by a split of the of the pictureimage into groups of pixels. The image from the DUT can be scanned outby row or column of image pixels in a left to right, top to bottom orright to left, bottom to top direction. When the image data is split,individual groupings of pixels within an image split are stored into thememories of the computational units. The split of the image data is donein a number of portions and distributed to the computational units 10within the frame grabber unit 20. The portions are by pixel or groups ofpixels. The groups of pixels can be by rows of pixels, columns of pixelsor clusters of pixels, which form a checkerboard like pattern on theimage. Distributing the image by pixel allows additional compution timethat can be done as additional pixels are coupled to the computationalunits.

Continuing to refer to FIG. 1B, the CPU 10 within each computationalunit (10) through computational unit (K) then performs calculation onthe data in memory 11 simultaneously and in parallel with all CPU 10.Many lengthy computations are performed comprising for exampleperforming Fast Fourier Transform (FFT); determining the modulationtransfer function (MTF) of the image versus the focus target, detectingnoise including fixed pattern noise (FPN), cross talk between colors oflight, test of the ADC in the PE16; detection of bad pixels, darkcurrent, noise including fixed pattern noise (FPN) and cross talkbetween colors; resolution measurements of the optics in the teststation; peak detection of the brightness of a pixel or portion of animage; averaging an image over several pixels; and detecting vignettingand distortion of the optics system. All of these computations that arenecessary to determine a good digital camera device (DUT) require a verylarge number of computations. As the pixel density increases in digitalcamera devices, more computational power is required so as to containthe test time of the DUT.

In FIG. 2 is shown a block diagram of a plurality of frame grabber units20, FGU(1) to FGU(M), coupled to a DUT 14. Frame grabber unit FGU(1)acts as a master and controls a light source 25 to illuminate 26 the DUT14. The light source 25 is controlled for color, intensity, light pulseshape and repetitiveness and is controlled to produce narrow lightpulses in the range of microseconds extending to milliseconds dependingupon the test being performed. The light source can be run continuously,repeating the light pulse and or any programmed repetition of a sequenceof light pulses. The master frame grabber FGU(1) synchronizes the lightsource with the clock of the DUT 14 so that an image of the light can becaptured by the DUT. Each frame grabber unit 20, FGU(1) to FGU(M),contain a plurality of computational units 10 as shown in FIG. 1B. Thepicture image coupled from the DUT 14 to the frame grabber units FGU(1)to FGU(M) is divided into portions and distributed to the Kcomputational units contained within each frame grabber unit 20.

In FIG. 3A is shown two DUT 14, DUT(1) and DUT(2). The two DUT 14 areeach connected to separate frame grabber units 20, DUT(1) to framegrabber unit FGU(1) and DUT(2) to frame grabber unit FGU(2). The DUT 14are controlled and provided signals from a stimulus and control unit 30.Each frame grabber unit 20 controls a separate light source 25, FGU(1)controls light source LS(1) to illuminate 26 DUT(1), and FGU(2) controlslight source LS(2) to illuminate 26 DUT(2). The light sources 25 arecontrolled by each frame grabber unit 20 to be synchronous with theclock of each respective DUT 14. This arrangement is necessary whenDUT(1) and DUT(2) cannot be positioned under the same light source asmight be the case if the DUT is a physical module located in twophysically separate test apparatus, or the two DUT are of different partnumbers requiring a difference in the illumination. The frame grabberunits 20, FGU(1) and FGU(2), contain a plurality of computational units10 as shown in FIG. 1B that operate simultaneously in parallel onportions of a picture image to calculate the image parameters.

In FIG. 3B there are two DUT 14, DUT(1) and DUT(2), controlled by thestimulus and control unit 30. DUT(1) is coupled to a frame grabber unitFGU(1) 20, which acts as a master for control of the light source 25illuminating 26 both DUT(1) and DUT(2), and FGU(2) is coupled to DUT(2).The master frame grabber FGU(1) synchronizes the clocks of DUT(1) andDUT(2) with the occurrence of the illumination 26 from the light source25 so that an image of the light can be captured by both DUT(1) andDUT(2). The light source 25 produces fast light pulses ranging frommicroseconds to milliseconds of a color of light. The light source has arange of colors that must be quickly switched between so as to notimpede the testing of the DUT. The range of colors comprise red, blue,green, infrared and any additional colors required in the testing of theDUT 14. Each frame grabber unit, FGU(1) and FGU(2), contain a pluralityof computational units 10 as shown in FIG. 1B.

FIG. 4A is a block diagram showing a plurality of frame grabber units 20contained within in two groups of frame grabber units 21, each group 21is connected to a DUT 14, DUT(1) and DUT(2). Each of frame grabber unit,FGU(1,1) to FGU(1,M) and FGU(2,1) to FGU(2,M) contain a plurality ofcomputational units 10 as shown in FIG. 1B. The frame grabber unitFGU(1,1) acts as a master to control the light source 25 LS(1) toilluminate 26 DUT(1), and frame grabber unit FGU(2,1) acts as a masterto control the light source 25 LS(2) to illuminate 26 DUT(2). The twoDUT 14, DUT(1) and DUT(2), can be the same part number or different partnumbers requiring separate light sources, or two devices or modulesphysically space such that a single light source cannot be used. Thestimulus and control unit 30 provides control signals to the DUT (1) andDUT(2), which when illuminated by the light sources LS(1) and LS(2)produce a picture image that is coupled to the groups of frame grabberunits 21. The Frame grabber unit FGU(1,1) synchronizes the occurrence ofthe illumination 26 with the clock of the DUT(1) and frame grabber unit(2,1) synchronizes the occurrence of the illumination 26 with the clockof the DUT(2). The picture data from DUT(1) is coupled to frame grabberunits FGU(1,1) to FGU(1,M) and is distributed to the K computationalunits 10 (FIG. 1B) contained within each frame grabber unit in a fashionthat divides the required calculations among the K computational units.In Like manner, the picture data from DUT(2) is coupled to frame grabberunits FGU(2,1) to FGU(2,M) and is distributed to the K computationalunits contained within each frame grabber unit. Each computational unit10 (FIG. 1A and 1B) operates in parallel, separately and independent ofthe other computational units to calculate the image parameters of thepicture images from DUT(1) and DUT(2) producing a maximum parallelcomputational performance that is proportional to the number ofcomputational units 10 that are being used.

FIG. 4B shows a configuration where a plurality of light sensitivedevices under test 14, DUT(1), DUT(2) to DUT(N) are coupled to aplurality of groups of frame grabber units 21, G=1, G=2 to G=N. Withineach group of frame grabber units 21 there are M frame grabber units 20,FGU(1,1) to FGU(1,M) in group G=1, FGU(2,1) to FGU(2,M) in group G=2 andFGU(N,1) to FGU(N,M) in group G=N. Each frame grabber unit 20, FGU(1,1)to FGU(1,M), FGU(2,1) to FGU(2,M) and FGU(N,1) to FGU(N,M), contain aplurality (1 to K) of computational units 10 as shown in FIG. 1B, whichprovides the computational power necessary to analyze a plurality ofpicture images to determine the capability of each DUT 14.

Continuing to refer to FIG. 4B, the image data is divided amongst thecomputational units 10 in each of the frame grabber units 20. Forexample, a portion P=1 of an image from DUT(1) is coupled tocomputational unit K=1 in frame grabber unit FGU(1,1), portion P=K iscoupled to computational unit K in FGU(1,1), portion P=K+1 is coupled tocomputational unit K=1 in FGU(2,1), and portion P=M×K is coupled tocomputational unit K in FGU(1,M). The results of the computations arestored back into the memory 11 by each CPU 12 and read by a hostcomputer 15 (FIG. 1A) to determine the composite result of each testperformed on each DUT 14.

Continuing to refer to FIG. 4B, the frame grabber unit FGU(1,1) acts asa master to control the light source 25 that illuminates 26 each of thedevices under test, DUT(1), DUT(2) to DUT(N). The devices under test 14are digital camera devices of a single part number in a chip formlocated on a semiconductor wafer, for example, or can be in a moduleform, where each DUT 14 is physically spaced such that one light sourcecan be used to illuminate all DUT simultaneously. The control of thelight source 25 comprises selecting a color of light, selecting a pulseshape, intensity and duration, and synchronizing the occurrence of theresulting illumination 26 with the clock of the plurality of DUT 14 sothat each DUT 14 can capture an image of the light. It is within thescope of this invention that there is a light source independentlycontrolled for each DUT 14, DUT(1), DUT(2) to DUT(N), by a frame grabberunit 20 in each group, G=1, G=2 to G=N. For example, a separate lightsource for DUT(1) could be controlled by FGU(1,1), a light source forDUT(2) controlled by FGU(2,1) and a light source for DUT(N) controlledby FGU(N,1). Independent light sources might be required when distancesare such that one light source cannot illuminate all of the devices 14.Also it should be noted that fewer than N light sources can be used, forexample a light source 25 is controlled by FGU(1,1) for DUT(1) throughDUT(N=4) and a second light source 25 is controlled by FGU(N=5,1) forDUT(N=5) to DUT(N).

In FIG. 5 is shown a method of computing the parameters of an image froma digital camera device (DUT). The image is divided into M portions 49.A first portion is coupled to an M=1 frame grabber unit 50, where M isthe number of frame grabber units. The first portion is divided into Ksub-portions and each of the K sub-portions are coupled to one of Kcomputational units within the M=1 frame grabber unit 51, where K is thenumber of computational units within a frame grabber unit. A secondportion is coupled to an M=2 frame grabber unit 52, and the secondportion is divided into K sub-portions and each sub-portion isdistributed to one of the K computational units contained within the M=2frame grabber unit 53. An M portion is coupled to an M frame grabberunit 54. The M portion is divided into K sub-portions, and eachsub-portion is distributed to one the K computational units containedwithin the M frame grabber unit 55. All K computational units within theM frame grabber units operate independently and in parallel tosimultaneously compute the image parameters for M×K sub-portions of theM portions 56. This results in a computational speedup of M×K ascompared to a single computation unit operating on the picture image.The results of the computations are stored back into the respectivememories of the computational units and coupled to the host computer 57for aggregating the computed results.

In FIG. 6 is shown a method in which image data is loaded into a framegrabber unit such that each computational unit within the frame grabberunit computes on pixels distributed to the computational units. Forexample, a first pixel P(1) of an image that is loaded into a firstcomputational unit 60, where P(1)=1, a second pixel is loaded into asecond computational unit 61, where P(2)=2, and a K pixel P(K)=K isloaded into a K computational unit 62. Computation of the parameters ofloaded pixels commences 63 while additional pixels of an image areloaded into the computational units 64, 66, 60, 61, and 62. The nextpixel P(1)=K+1 is coupled to the first computational unit 60, pixelP(2)=K+2 is coupled to the second computational unit, and pixel P(K)=2Kis loaded into the K computational unit. The loading of pixels continuesuntil pixel P(K)=Pmax is loaded into a computational unit 65. Theresults of the computations are stored in the respective computationalunit memory 67. For example, computed results for the first pixel isstored in the memory of the first computational unit and the computedresults for the second pixel is stored in the memory of the secondcomputational unit. When the computational process finishes, the resultsstored in the memories of the computational units are coupled to thehost computer 68 where the results are combined and analyzed to providea final composite test results.

In FIG. 7 is shown a method for analyzing a plurality of N imagescreated by a plurality of digital camera devices (N-DUT), DUT(1) throughDUT(N), that are being tested simultaneously, where N is an integerrepresenting a particular DUT. Referring to FIG. 1B and 4B along withFIG. 7, the N-DUT are illuminated with light from a light source andeach N-DUT is controlled to capture an image of the light, totaling Nimages, one image for each DUT 70. A first image from DUT(1) is coupledto a first group (G=1) of frame grabber units 71. Each frame grabberunit FGU(1,1) through FGU(1,M) within group (G=1) contains Kcomputational units. The first image is divided into portions P amongsteach of the K computational units within each of the frame grabber unitsFGU(1,1) through FGU(1,M) 72. For example, a first portion (P=1) of thefirst image is coupled to the first computational unit (K=1) in framegrabber unit FGU(1,1), the second portion (P=2) of the first image iscoupled to the second computational unit (K=2) of FGU(1,1), the P=K+1image portion is coupled to the first computational unit K=1 of theframe grabber unit FGU(1,2), and so on until the last portion P=M×K ofthe first image is coupled to the last computational unit K of FGU(1,M),where the total image portions P is equal to the number of M framegrabber units times K computational units in each frame grabber unit,P=M×K.

Continuing to refer to FIG. 7, a second image from DUT(2) is coupled toa second group (G=2) frame grabber units 73. The second image is dividedamongst each of K computational units of the second group (G=2) of Mframe grabber units 74 in a similar fashion as was done for the firstimage. For example, a first image portion (P=1) of the second image iscoupled to the first computational unit (K=1) in frame grabber unitFGU(2,1), the second portion (P=2) of the second image is coupled to thesecond computational unit (K=2) of FGU(2,1), the (P=K+1) image portionis coupled to the first computational unit (K=1) of the frame grabberunit FGU(2,2), and so on until the last portion (P=M×K) of the firstimage is coupled to the last computational unit (K) of FGU(2,M),

The process of coupling the images from the N digital camera devicescontinues until the image of the last DUT(N) is coupled to the framegrabber group (G=N) 75. The last image from the last DUT(N) is dividedamongst each of K computational units of the last group (G=N) of M framegrabber units 76 in a similar fashion as was done for the image fromDUT(1). For example, a first image portion (P=1) of the last image iscoupled to the first computational unit (K=1) in frame grabber unitFGU(N,1), the second portion (P=2) of the last image is coupled to thesecond computational unit (K=2) of FGU(N,1), the (P=K+1) image portionis coupled to the first computational units (K=1) of the frame grabberunit FGU(N,2), and so on until the last portion (P=M×K) of the lastimage is coupled to the last computational unit K of FGU(N,M). Theresults of the computations are coupled to a host computer 78 for thecombining of the results to determine the quality of the digital cameradevices.

Continuing to refer to FIG. 7, there are P=M×K×N image portions that arecalculated in parallel by M×K×N computational units. The portions of theimage data are independent and separate from each other allowing eachCPU 12 (FIG. 1A) to perform at a maximum computational rate. As the datais being loaded into each computational unit, computation commences onthe loaded portion of the data as the remainder of the data is loaded tomaximize the overlap of data loading and computation in order to improvetotal test time. The data can be loaded pixel by pixel. For example thefirst pixel (p=1) of an image is coupled to the first computational unit(K=1) of the frame grabber unit FGU(1,1), the second pixel (p=2) coupledto the second computational unit (K=2) of FGU(1,1), the (p=K) pixelcoupled to the last computational unit K of FGU(1,1), the (p=K+1) pixelcoupled to the first computational unit (K=1) of FGU(1,2), and the(p=K×M) pixel coupled to the computational unit K of FGU(1,M).Computation is started when the first pixel data is loaded whileadditional image data is loaded by coupling the (p=K×M+1) pixel into thefirst computational unit (K=1) of FGU(1,1), the (p=K×M+2) pixel intocomputational unit (K=2) of FGU(1,1), the (p=K×(M+1)) pixel intocomputational unit K of FGU(1,1), the (p=K×(M+1)+1) pixel intocomputational unit (K=1) of FGU(1,2), so on until the (p=2K×M) pixel iscoupled to the computational unit K of FGU(1,M), and returning to thefirst computational unit (K=1) in FGU(1,1) for the next pixel. This loada pixel and begin computing procedure provides a way to have a maximumoverlap between loading image data and computing image parameters. Analternative to loading pixel by pixel is to load the computational unitsby row or column, groups of rows or columns, or other grouping of pixelssuch as groups of pixels clustered in a checkerboard fashion.

In FIG. 8 is shown a method of performing image tests on a plurality ofdigital camera devices (N-DUT) simultaneously. A computational unit isformed containing a memory and a computer 90. A frame grabber unit isformed containing K computational units 91. A group of frame grabberunits is formed containing M frame grabber units 92. Electrical contactis made to N-DUT 93 allowing N groups of frame grabber units to becoupled to the N-DUT 94. The N-DUT are illuminated by a single lightsource 95 controlled by a master frame grabber unit 96. The master framegrabber unit can be any of the M frame grabber units. The light sourceis controlled for light parameters comprising color, intensity, pulseshape, duration, and repetitiveness. The N-DUT are controlled to produceN picture images 97, and the N picture images are coupled to N groups offrame grabber units 98. Each of the N images is coupled to N groups offrame grabber units and is distributed to the K computational unitscontained within the M frame grabber units 99. Image parameters arecalculated using the K computational units, operating simultaneously,that are located within each of the N groups of frame grabber units 100.The results of the computation are stored into the computationalmemories and coupled to a host computer for combining the final resultsto determine the quality of the N-DUT 101.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade without departing from the spirit and scope of the invention.

1. A method of parallel processing a picture image from a digital cameradevice, comprising: a) dividing a picture image from a digital cameradevice into M portions, b) coupling said M portions to M frame grabberunits, in which each frame grabber unit contains K computational units,c) dividing said M portions into K sub-portions and coupling said Ksub-portions to said K computational units, d) calculating parameters ofsaid picture image with said M×K computational units, e) couplingresults of said calculations to a host computer.
 2. The method of claim1, wherein said sub-portions are by groups of pixels of said pictureimage.
 3. The method of claim 2, wherein said groups of pixels are byrow of pixels of said picture image.
 4. The method of claim 2, whereinsaid groups of pixels are by column of pixels of said picture image. 5.The method of claim 2, wherein said groups of pixel are by clusters ofpixels forming a checkerboard configuration.
 6. The method of claim 1,wherein said calculating parameters of said picture image is performedby said computational units in parallel yielding a performance speedupof M×K compared to the performance obtained using one computationalunit.
 7. A method for parallel processing a picture image by pixel,comprising: a) coupling a picture image to a frame grabber unitcontaining K computational units, b) distributing said picture image tosaid K computational units by pixel, c) starting with a firstcomputational unit of said K computational units, coupling a firstpixel, continuing to the next computational unit until the lastcomputational unit of said K computational units is coupled with a Kpixel, then returning to the first computational unit to load a K+1pixel and continuing in this fashion until all pixels of said pictureimage is coupled to the K computational units, d) commencingcalculations of image parameters on the pixels of said picture image asadditional pixels are coupled to said computational units, e) couplingresults of said calculations to a host computer to be combined todetermine a final result of the calculations of said picture image. 8.The method of claim 7, wherein said pixels are coupled to said Kcomputational units by row of pixels of said picture image.
 9. Themethod of claim 7, wherein said pixels are coupled to said Kcomputational units by column of pixels of said picture image.
 10. Theimage of claim 7, wherein said pixels are coupled by a group of pixelshaving a checkerboard pattern within said picture image.